Piezoelectric blower

ABSTRACT

Embodiments of the invention provide a piezoelectric blower, including a first diaphragm comprising a first piezoelectric element disposed at an outer surface thereof, a second diaphragm comprising a second piezoelectric element disposed at the outer surface thereof and disposed to be spaced, in parallel, apart from the first diaphragm, and a rim disposed along circumferences of an edge of the first diaphragm and an edge of the second diaphragm. The piezoelectric blower further includes a blower chamber defined by the first diaphragm, the second diaphragm, and the rim, and an opening through which air is sucked and discharged into and from a blower chamber.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of and priority under 35 U.S.C. §119 to Korean Patent Application No. KR 10-2014-0002481, entitled “PIEZOELECTRIC BLOWER,” filed on Jan. 8, 2014, which is hereby incorporated by reference in its entirety into this application.

BACKGROUND

1. Field of the Invention

The present invention relates to piezoelectric blower.

2. Description of the Related Art

Generally, as various types of electronic devices, such as computer/television tend to be multi-functional, miniaturized, and continuously used, heat is generated inside the electronic devices. The heat generation phenomenon acts as main factors to reduce performance of the electronic devices.

Therefore, various types of electronic devices include at least one cooling means formed at heat generation parts thereof. The cooling means, according to the conventional art mainly adopts a fan type of cooling means, which is already well known, in which the fan type of cooling means has problems with required power consumption to drive the fan and noise generated due to a rotation of the fan, and is difficult to miniaturize and make thin to be implemented in electronic devices which tend to be miniaturized.

To solve the problems, those skilled in the art have proposed a pump, described, for example, in Japanese Patent Publication No. 2012-107636, which provides a piezoelectric-type pump providing an air stream to surrounding environments through repetitive expansion and contraction deformations at the time of application of power is applied.

In particular, Japanese Patent Publication No. 2012-107636 proposes a piezoelectric micro pump, which is driven with a flexural displacement of a piezoelectric element, as generally described above, and the piezoelectric micro pump is configured to include a lower plate having an opening, an upper plate including an opening, and a diaphragm disposed to cross between the upper plate and the lower plate. The diaphragm partitions a fluid chamber defined by the upper plate and the diaphragm, and a pump chamber defined by the lower plate and the diaphragm and is driven with a flexurally displaceable piezoelectric element.

The pump to which the piezoelectric type of Japanese Patent Publication No. 2012-107636 is applied is translated in a vertical direction of the diaphragm interposed between the upper plate and the lower plate, as generally described above, to cause a vibrating force, thereby sucking and/or discharging the fluid. A stack structure in which the diaphragm is interposed between the upper plate and the lower plate is difficult to secure a reliably sealed state. Further, the pump described in Japanese Patent Publication No. 2012-107636 relies on only the expansion and/or contraction of the piezoelectric element mounted in the diaphragm, and thus may have a weak vibration force and may be easily damaged due to a collision with the piezoelectric element of the diaphragm and the upper plate (or lower plate).

SUMMARY

Accordingly, embodiments of the invention have been made in an effort to provide a blower capable of forming an air stream by vertically translating each of the two diaphragms arranged in parallel.

According to at least one embodiment, there is provided a piezoelectric blower, including a first diaphragm having a first piezoelectric element disposed at an outer surface thereof, and a second diaphragm having a second piezoelectric element disposed at the outer surface thereof and disposed to be spaced, in parallel, apart from the first diaphragm. The piezoelectric blower further includes a rim disposed along circumferences of an edge of the first diaphragm and an edge of the second diaphragm, a blower chamber defined by the first diaphragm, the second diaphragm, and the rim, and an opening through which air is sucked and discharged into and from a blower chamber.

According to an embodiment, the first piezoelectric element and the second piezoelectric element are disposed in an opposite direction to each other.

According to an embodiment, the first piezoelectric element is disposed at a central portion of the first diaphragm and the second piezoelectric element is disposed at a central portion of the second diaphragm. According to an embodiment, the two piezoelectric elements are disposed at a central portion of the diaphragm, in which the vertical vibration displacement of the diaphragm is generally largest; and therefore, the piezoelectric elements are disposed at the central portion to increase the vibrating force.

According to an embodiment, the piezoelectric blower further includes an elastic member between an inner surface of the first diaphragm and an inner surface of the second diaphragm.

According to an embodiment, the elastic member is interposed between a central portion of the inner surface of the first diaphragm and a central portion of the inner surface of the second diaphragm, but, according to another embodiment, the elastic member is disposed between the first piezoelectric element and the second piezoelectric element. The elastic member prevents contact between the first piezoelectric element and the second piezoelectric element and amplifies the vibrating force of the diaphragm flexurally vibrated.

According to an embodiment, the elastic member is formed of a coil spring.

According to an embodiment, the opening is formed between the edge of the first diaphragm and the edge of the second diaphragm.

According to an embodiment, the rim has a C-letter sectional shape.

According to an embodiment, the rim is made of an elastic material.

Various objects, advantages and features of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

These and other features, aspects, and advantages of the invention are better understood with regard to the following Detailed Description, appended Claims, and accompanying Figures. It is to be noted, however, that the Figures illustrate only various embodiments of the invention and are therefore not to be considered limiting of the invention's scope as it may include other effective embodiments as well.

FIG. 1 is a perspective view schematically showing a piezoelectric blower according to an embodiment of the invention.

FIG. 2 is an exploded perspective view of a piezoelectric blower illustrated in FIG. 1 according to an embodiment of the invention.

FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 1 according to an embodiment of the invention.

FIGS. 4A and 4B are schematic views illustrating an operation configuration of a piezoelectric blower according to an embodiment of the invention.

DETAILED DESCRIPTION

Advantages and features of the present invention and methods of accomplishing the same will be apparent by referring to embodiments described below in detail in connection with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The embodiments are provided only for completing the disclosure of the present invention and for fully representing the scope of the present invention to those skilled in the art.

For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the discussion of the described embodiments of the invention. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a piezoelectric blower according to various embodiments of the invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view schematically showing a piezoelectric blower according to an embodiment of the invention, FIG. 2 is an exploded perspective view of a piezoelectric blower illustrated in FIG. 1 according to an embodiment of the invention, and FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 1 according to an embodiment of the invention.

Referring to FIGS. 1 to 3, a piezoelectric blower 1, according to an embodiment of the invention, is configured to include a pair of diaphragms 100 and 200, which are disposed to be spaced, in parallel, apart from each other, a rim 300, which seals circumferences of edges of the pair of diaphragms 100 and 200, and an elastic member 500 interposed between the pair of diaphragms 100 and 200.

According to an embodiment of the invention, the diaphragms 100 and 200 are flexurally vibrated with a vibrating force of piezoelectric elements 130 and 230 by repeatedly expanding and contracting modification of the piezoelectric elements 130 and 230 to forcibly suck and/or discharge a fluid (preferably, air) into and/or from a blower chamber 400 to supply the fluid to a specific portion, for example, a heat generation portion.

According to an embodiment, the diaphragms 100 and 200 are formed of a thin plate having elasticity to be flexurally vibrated integrally with the piezoelectric elements 130 and 230, repeatedly expanded and contracted depending on the application of power. According to an embodiment, the diaphragms 100 and 200 are formed of one of a metal plate, a glass epoxy plate, a resin sheet, or a rubber sheet, as non-limiting examples. In accordance with at least one embodiment, the diaphragms 100 and 200 include a plate having low Young's modulus and a thin thickness. The illustrated diaphragms 100 and 200 have a quadrangular plate, but, according to at least one embodiment, they may be manufactured in various shapes, such as an oval shape, a circular shape, or a triangular shape, as non-limiting examples.

According to an embodiment, first diaphragm 100 includes a first piezoelectric element 130 formed on outer surface thereof by a bonding method. Meanwhile, the second diaphragm 200 includes a second piezoelectric element 230 formed on an outer surface 210 thereof and has the same shape and size as the first diaphragm 100. As illustrated, for example in FIGS. 1-3, the first piezoelectric element 130 and the second piezoelectric element 230 are disposed in an opposite direction to each other and thus do not contact each other.

According to an embodiment, the first and second piezoelectric elements 130 and 230 are configured by being stacked in a single layer form or a multilayer form. The piezoelectric elements 130 and 230 stacked in the multilayer form secure an electric field required to drive the piezoelectric elements 130 and 230, even in low external voltage. Therefore, various embodiments of the invention lower driving voltage of the piezoelectric blower 1; and therefore, in various embodiments of the invention, the piezoelectric elements 130 and 230 stacked in the multilayer form are adopted.

According to an embodiment of the invention, the piezoelectric blower 1 includes printed circuit boards (PCBs) 140 and 240, or a flexible printed circuit board (FPCB), which is connected to electrodes included in the first and second piezoelectric elements 130 and 230 to supply power to the first and second piezoelectric elements 130 and 230.

According to an embodiment, the piezoelectric blower 1, according to an embodiment of the invention, includes a rim 300, which is disposed along the circumferences of the edges of the first and second diaphragms 100 and 200 to fix the first and second diaphragms 100 and 200, which are spaced apart from each other in parallel.

As illustrated in FIGS. 1-3, the rim 300 is disposed between the edge of the first diaphragm 100 and the edge of the second diaphragm 300 to seal between the diaphragms 100 and 200, and the rim 300, thereby securing air tightness. Alternatively, the rim 300, according to another embodiment, has a C-letter sectional shape, and the edge of the first diaphragm 100 is fixed to an upper portion of the rim 300, while the edge of the second diaphragm 200 is fixed to a lower portion of the rim 300. According to another embodiment, the rim 300 is made of an elastic material and increases an amplitude displacement of the diaphragm at the time of flexurally vibrating the diaphragms 100 and 200.

In addition, the piezoelectric blower 1, according to an embodiment of the invention includes, a blower chamber 400, which is defined by the first diaphragm 100, the second diaphragm 200, and the rim 300. The blower chamber 400 communicates with air through the flexural vibration of the first diaphragm 100 and the second diaphragm 200, and thus receives the air.

According to an embodiment of the invention, the blower chamber 400 is provided with an opening 600 through which air is discharged and sucked. The opening 600 is formed between the edge of the first diaphragm 100 and the edge of the second diaphragm 200. but is not sealed by the rim 300. Unlike this, the rim 300 seals the diaphragms 100 and 200 by completely enclosing the edges of the diaphragms 100 and 200 and the opening is also partially formed at a portion of the rim 300.

As illustrated in FIG. 3, the opening 600 is formed between the first diaphragm 200 and the second diaphragm 200 to induce air stream in a horizontal direction. An embodiment of the invention is not limited thereto, but the opening 600 is formed in the first diaphragm 100 and/or the second diaphragm 200 to induce air stream in a vertical direction.

When power is applied to each of the piezoelectric elements 130 and 230, the piezoelectric elements 130 and 230 are attached to the outer surfaces 110 and 210 of the first diaphragm 100 and the second diaphragm 200, which are flexurally vibrated, and thus are expanded and/or contracted, thereby generating a moment at the central portions of the first and second diaphragms 100 and 200. As described above, since the moment is generated in the state in which the first and second diaphragms 100 and 200 are fixed to the rim 300, the central portions of the first and second diaphragms 100 and 200, according to an embodiment of the invention, vertically move in a dome shape. Therefore, according to an embodiment of the invention, to increase the moving widths of the first and second diaphragms 100 and 200, the first piezoelectric element 130 is disposed at the central portion of the first diaphragm 100, while the second piezoelectric element 230 is disposed at the central portion of the second diaphragm 200.

Preferably, in the piezoelectric blower 1, according to an embodiment of the invention, as shown in FIGS. 4A and 4B, an elastic member 500 is disposed between an inner surface 120 of the first diaphragm 100 and an inner surface 220 of the second diaphragm 200. The elastic member 500 is disposed between the central portions of the diaphragms 100 and 200 of which the amplitude displacement is maximal to support the diaphragms 100 and 200, which are disposed in parallel. As the result, according to an embodiment of the invention, a vibrating force is added to the first and second diaphragms 100 and 200 by the tension and/or compression of the elastic member 500, when the first and second diaphragms 100 and 200 are vertically displaced, thereby increasing the flexural vibration frequency per unit time. In addition, the elastic member 500 serves as a stopper preventing a direct collision between the first diaphragm 100 and the second diaphragm 200 at the time of compression. When there is no elastic compression 500, when the first diaphragm 100 and the second diaphragm 200 collide with each other due to the abnormal driving, the piezoelectric elements 130 and 230 are highly likely to be damaged. The elastic member 500 is also a coil spring.

FIGS. 4A and 4B are schematic views illustrating an operation configuration of a piezoelectric blower according to an embodiment of the invention.

FIG. 4A is a cross-sectional views of the piezoelectric blower 1 in which the lengths of the piezoelectric elements 130 and 230 are extended when the piezoelectric elements 130 and 230 are applied with power, for example, when the lengths of the piezoelectric elements 130 and 230 are long, the diaphragms 100 and 200 have a relatively small deformation rate and the edges of the diaphragms 100 and 200 are fixed to the rim 300, such that the first diaphragm 100 is driven, being bent downward. On the other hand, the second diaphragm 200 has the second piezoelectric element 230 being differently disposed from each other and are disposed, being bent upwardly. As such, the volume of the blower chamber 400 between the first and second diaphragms 100 and 200 is minimal; and therefore, the air staying in the blower chamber 400 is discharged through the opening 600.

In contrast, FIG. 4B is a cross-sectional view of the piezoelectric blower 1 in which the lengths of the piezoelectric elements 130 and 230 are contracted when the piezoelectric elements 130 and 230 are applied with power and when the lengths of the piezoelectric elements 130 and 230 are reduced, the first diaphragm 100 is driven, being bent upwardly, but the second diaphragm 200 is driven, being bent downwardly. In this case, the blower chamber 400 sucks the air, while keeping the maximum volume.

As described above, the piezoelectric blower 1 periodically repeats the suction and discharge of air by flexurally vibrating the first diaphragm 100 and the second diaphragm 200 to form the forced air stream in the surrounding air, in which the air stream radiates heat of the heat generation portion.

As described above, according to various embodiments of the invention, it is possible to provide a piezoelectric blower, which generates a movement (or air stream) of a fluid with the low power by adopting the piezoelectric element.

Further, according to various embodiments of the invention, the fluid of the surrounding environments are repeatedly sucked and discharged by operating the two diaphragms arranged in parallel to face each other as the piezoelectric device to blow the air stream into the heat generation portion, thereby lowering the temperature.

In addition, according to various embodiments of the invention, the two diaphragms are operated only in the vertical translation, such that the blower generates minimal noise and is manufactured in a small and thin form.

Terms used herein are provided to explain embodiments, not limiting the present invention. Throughout this specification, the singular form includes the plural form unless the context clearly indicates otherwise. When terms “comprises” and/or “comprising” used herein do not preclude existence and addition of another component, step, operation and/or device, in addition to the above-mentioned component, step, operation and/or device.

Embodiments of the present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.

The terms and words used in the present specification and claims should not be interpreted as being limited to typical meanings or dictionary definitions, but should be interpreted as having meanings and concepts relevant to the technical scope of the present invention based on the rule according to which an inventor can appropriately define the concept of the term to describe the best method he or she knows for carrying out the invention.

The terms “first,” “second,” “third,” “fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Similarly, if a method is described herein as comprising a series of steps, the order of such steps as presented herein is not necessarily the only order in which such steps may be performed, and certain of the stated steps may possibly be omitted and/or certain other steps not described herein may possibly be added to the method.

The singular forms “a,” “an,” and “the” include plural referents, unless the context clearly dictates otherwise.

As used herein and in the appended claims, the words “comprise,” “has,” and “include” and all grammatical variations thereof are each intended to have an open, non-limiting meaning that does not exclude additional elements or steps.

As used herein, the terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein. The term “coupled,” as used herein, is defined as directly or indirectly connected in an electrical or non-electrical manner. Objects described herein as being “adjacent to” each other may be in physical contact with each other, in close proximity to each other, or in the same general region or area as each other, as appropriate for the context in which the phrase is used. Occurrences of the phrase “according to an embodiment” herein do not necessarily all refer to the same embodiment.

Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.

Although the present invention has been described in detail, it should be understood that various changes, substitutions, and alterations can be made hereupon without departing from the principle and scope of the invention. Accordingly, the scope of the present invention should be determined by the following claims and their appropriate legal equivalents. 

What is claimed is:
 1. A piezoelectric blower, comprising: a first diaphragm comprising a first piezoelectric element disposed at an outer surface thereof; a second diaphragm comprising a second piezoelectric element disposed at the outer surface thereof and disposed to be spaced, in parallel, apart from the first diaphragm; a rim disposed along circumferences of an edge of the first diaphragm and an edge of the second diaphragm; a blower chamber defined by the first diaphragm, the second diaphragm, and the rim; and an opening through which air is sucked and discharged into and from a blower chamber.
 2. The piezoelectric blower according to claim 1, wherein the first piezoelectric element and the second piezoelectric element are disposed in an opposite direction to each other.
 3. The piezoelectric blower according to claim 1, wherein the first piezoelectric element is disposed at a central portion of the first diaphragm and the second piezoelectric element is disposed at a central portion of the second diaphragm.
 4. The piezoelectric blower according to claim 1, further comprising: an elastic member disposed between an inner surface of the first diaphragm and an inner surface of the second diaphragm.
 5. The piezoelectric blower according to claim 4, wherein the elastic member is interposed between a central portion of the inner surface of the first diaphragm and a central portion of the inner surface of the second diaphragm.
 6. The piezoelectric blower according to claim 4, wherein the elastic member is formed of a coil spring.
 7. The piezoelectric blower according to claim 1, wherein the opening is formed between the edge of the first diaphragm and the edge of the second diaphragm.
 8. The piezoelectric blower according to claim 1, wherein the opening is formed on the rim.
 9. The piezoelectric blower according to claim 1, wherein the rim comprises a C-letter sectional shape.
 10. The piezoelectric blower according to claim 1, wherein the rim is made of an elastic material. 